TW201843189A - Removable radiation-curable silicone composition and release sheet - Google Patents

Abstract

Provided are: a removable radiation-curable silicone composition which has excellent radiation curability and gives cured objects having excellent adhesiveness to the substrates; and a release sheet. The removable radiation-curable silicone composition comprises the following components (A), (B), (C), and (D): (A) 100 parts by mass of an organopolysiloxane having an alkenyl group; (B) 1-30 parts by mass of an organopolysiloxane having a mercaptoalkyl group; (C) 0.1-5 parts by mass of a compound having a plurality of acryl groups in the molecule; and (D) 0.1-15 parts by mass of a photopolymerization initiator.

Description

Peelable radiation-hardenable polysiloxane composition and peeling sheet

The present invention relates to a radiation-curable polysiloxane composition and a release sheet that are excellent in radiation curability and obtain a cured product having excellent adhesion to a substrate.

Apply the organopolysiloxane composition on the surface of substrates such as various papers, laminated papers, synthetic films, transparent resins, and metal foils, and form a hardened film by cross-linking reaction to produce adhesive or adhesive substances. A release sheet such as a release paper or a release film. Various methods are used to harden the organopolysiloxane composition. It is known that condensation reactions caused by organometallic compounds, sulfurization using organic peroxides, and hydrosilation reactions caused by platinum group metal catalysts are known. Wait. However, it is necessary to heat in the above-mentioned hardening method. In order to improve productivity or save energy, hardening at a lower temperature or room temperature is required. On the other hand, as a hardening method other than heating, a hardening method by radiation is used.

Radiation-based curing methods include radical polymerization using acrylic modified polysiloxane, cationic polymerization due to ring opening of epoxy groups of epoxy modified polysiloxane, and mercapto-modified polyorganosiloxane. Hardening caused by ene-thiol reaction of oxane.

Those who form a hardened film by free radical polymerization of acrylic modified polysiloxane using a photo radical initiator, although have high adhesion to the substrate and good hardenability, but the presence of oxygen hinders hardening, Must be used for devices that reduce oxygen concentration.

Those who form a hardened film by cationic polymerization of epoxy-modified polysiloxane with photo-acid generator ring-opening, although hardened by oxygen, can harden in air, but When the base material contains a compound that can inhibit the generation of acid, or due to the influence of humidity in the air, the hardening is likely to occur.

The formation of a hardened film by the ene-thiol reaction of a mercapto-modified polyorganosiloxane using a photo-radical initiator is the same as that in the case of acrylic-modified polysiloxane, although it is performed by radical polymerization Hardening, but has the advantage that it is not affected by the concentration of oxygen, can be hardened in the air, and is different from cationic polymerization, and is not easily affected by hardening inhibitors. Thereby, it is also possible to develop a back surface treatment agent for adhesive tapes, which is a base material containing various additives, a release agent for adhesive labels, an adhesive tape, and the like, and the market expansion can be expected in the future. Based on the above, many inventions related to a release agent for an ene-thiol reaction using a mercapto-modified polyorganosiloxane are proposed.

On the other hand, the radical polymerization caused by the ene-thiol reaction is different from the radical polymerization caused by the acrylic group. Although it can be hardened without being affected by the oxygen concentration in the air, the reaction rate is slower than the acrylic group Induced radical polymerization tends to reduce the adhesion of the substrate, in particular.

Japanese Invention Patent No. 3060868 (Patent Document 1) proposes a peelable UV-curable polysiloxane composition, which is characterized in that the viscosity at 25 ° C is 10,000 cp or more and the main component is: (A): in 1 molecule An organopolysiloxane having at least 2 alkenyl groups bonded to a silicon atom and having a viscosity of 100 to 10,000 cp at 25 ° C, (B): Alkenyl having at least 2 silicon atoms bonded in one molecule Organic polysiloxanes having a viscosity at 25 ° C of 1 million cp or more, rhenium (C): organic polysiloxanes having at least two mercaptoalkyl groups bonded to silicon atoms in one molecule, rhenium (D): Light initiator. In this invention, by adding the high-viscosity organopolysiloxane of the component (B), slipperyness is imparted to the hardened film, and various kinds of adhesive substances are lightly peeled off. The crosslinking density is caused by the addition of the component (B) If it decreases, the adhesiveness to the substrate may decrease.

Japanese Patent Publication No. 3394164 (Patent Document 2) proposes a peelable UV-curable polysiloxane composition whose main components are: (1): 1 to 3 branch structures are contained in one molecule on average. 100 parts by weight of an alkenyl-containing organopolysiloxane having a viscosity of 100 to 100,000 CP at 25 ° C (2): An organopolysiloxane containing at least two mercaptoalkyl groups bonded to a silicon atom in one molecule 1 ~ 30 parts by weight (3): a photoinitiator compatible with the above-mentioned organic polysiloxane. This invention uses (1) branched organic alkenyl group-containing organopolysiloxanes to increase the hardenability, but the branch structure is small and contains an average of 1 to 3 molecules per molecule. Sex is difficult to raise. [Prior Art Literature] [Patent Literature]

[Patent Literature 1] Japanese Invention Patent No. 3060868 [Patent Literature 2] Japanese Invention Patent No. 3394164 [Patent Literature 3] Japanese Patent Laid-Open No. 2016-041774

[Problems to be Solved by the Invention]

The present invention has been made in view of the foregoing circumstances, and an object thereof is to provide a peelable radiation-curable polysiloxane composition and a release sheet which are excellent in radiation curability and obtain a cured product having excellent adhesion to a substrate. [Means for solving problems]

The present inventors conducted an intensive review in order to achieve the above-mentioned object, and as a result, found that the release property for a release sheet to which a photoinitiator is added in an organopolysiloxane containing alkenyl groups and an organopolysiloxane containing mercapto groups is found. In the radiation-curable composition, a small amount of a compound having a plurality of acrylic groups in one molecule is added as an adhesion-enhancing agent without changing the peeling characteristics, and a release sheet that can significantly improve the adhesion to a substrate can be produced. Achieve the above issues. Therefore, in comparison with the conventional radiation-curable polysiloxane composition, it was confirmed that the peelable radiation-curable polysiloxane composition of the present invention obtained a cured product having good adhesion and maintaining peeling properties, and finally completed the present invention.

Therefore, the present invention provides the following inventions. [1]. A peelable radiation-curable polysiloxane composition containing the following components (A), (B), (C), and (D); (A) is represented by the following average composition formula (1) Organic polysiloxane with alkenyl group: 100 parts by mass (In the formula, R ¹ is a monovalent hydrocarbon group having the same or different carbon number 1 to 10; a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, and 2 ≦ a + b + c + d ≦ 8,000; However, R ¹ , a, b, c, and d are selected such that the alkenyl group bonded to the silicon atom in one molecule becomes two or more); (B) has the following average composition formula (2): Mercapto alkyl organic polysiloxane: 1 to 30 parts by mass (In the formula, R ² is a monovalent hydrocarbon group or mercapto alkyl group having the same or different carbon number 1 to 10; e ≧ 0, f ≧ 0, g ≧ 0, h ≧ 0, and 2 ≦ e + f + g + h ≦ 300; however, R ² , e, f, g, and h are selected so that the number of mercaptoalkyl groups bonded to the silicon atom in one molecule becomes two or more); (C) a compound having one in plural molecules Acrylic-based compound: 0.1 to 5 parts by mass (D) Photopolymerization initiator: 0.1 to 15 parts by mass. [2]. The peelable radiation-curable polysiloxane composition according to [1], wherein the component (C) is a compound having three or more acrylic groups in one molecule. [3]. The peelable radiation-curable polysiloxane composition according to [2], wherein the component (C) is a hydrocarbon compound having three or more acrylic groups in one molecule. [4]. The peelable radiation-curable polysiloxane composition according to [2], wherein the component (C) is a silane compound or a hydrolyzed condensate thereof having three or more acrylic groups in one molecule. [5]. A release sheet, which is a substrate in which the peelable radiation-curable polysiloxane composition according to any one of [1] to [4] is coated and cured by irradiation with radiation. [Effect of the invention]

According to the present invention, it is possible to provide a peelable radiation-curable polysiloxane composition and a release sheet which are excellent in radiation curability and obtain a cured product having excellent adhesion to a substrate.

[Mode for Carrying Out the Invention]

Hereinafter, the present invention will be described in detail. The peelable radiation-curable polysiloxane composition of the present invention contains the components (A), (B), (C), and (D). [(A) component] (A) component is an organic polysiloxane having an alkenyl group represented by the following average composition formula (1), (In the formula, R ¹ is a monovalent hydrocarbon group having the same or different carbon number 1 to 10; a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, and 2 ≦ a + b + c + d ≦ 8,000; However, R ¹ , a, b, c, and d are selected so that the alkenyl group bonded to the silicon atom in one molecule becomes two or more); they may be used alone or in a suitable combination of two or more.

In the formula, R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms of the same or different species, and is selected so as to contain two or more alkenyl groups having 1 to 10 carbon atoms bonded to a silicon atom in one molecule. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl, cycloalkyl groups such as cyclohexyl, vinyl, allyl, butenyl, and hexyl Alkenyl groups such as alkenyl, octenyl, aryl groups such as phenyl, tolyl, and the like, and further include a part or all of hydrogen atoms bonded to carbon atoms of these groups via fluorine, chlorine, etc. 3,3,3-trifluoropropyl, perfluorobutylethyl, perfluorooctylethyl substituted by a halogen atom, (meth) acrylic acid functionalized by propylene alkoxy, methacryl oxy and the like 3-methacryloxypropyl, 3-propenyloxypropyl substituted by a phenyl group, a polyoxyalkylene group substituted with a polyoxyethylene group, a polyoxypropylene group, or the like Unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms selected from methoxypropyl and ethoxypropyl. The component (A) is an alkenyl group containing two or more bonds to silicon atoms in one molecule. The alkenyl group is preferably a vinyl group, an allyl group, or a hexenyl group.

In addition, as the group other than the alkenyl group, 1 to 10 mole% of all R ¹ in the molecule is preferably a phenyl group, and the others are methyl groups from the viewpoint of peeling characteristics. When the phenyl content is less than 1 mol%, the ultraviolet curability is lowered, and when it exceeds 10 mol%, it is not suitable for peeling a sheet due to heavy peeling.

R ¹ , a, b, c, and d are selected so that the number of alkenyl groups bonded to a silicon atom in one molecule becomes two or more, preferably three or more, and the amount of alkenyl groups and phenyl groups can be as described above. The way shown values are chosen. The preferred ranges are a ≧ 2, b ≧ 50, c ≧ 0, d ≧ 0, and more preferably a ≧ 2, b ≧ 100, c ≧ 0, and d = 0. In addition, 2 ≦ a + b + c + d ≦ 8,000, and preferably 2 ≦ a + b + c + d ≦ 5,000.

[(B) component] (B) component is an organopolysiloxane having a mercaptoalkyl group represented by the following average composition formula (2), (In the formula, R ² is a monovalent hydrocarbon group or mercapto alkyl group having the same or different carbon number 1 to 10; e ≧ 0, f ≧ 0, g ≧ 0, h ≧ 0, and 2 ≦ e + f + g + h ≦ 300; however, R ² , e, f, g, and h are selected in such a way that the mercaptoalkyl group bonded to the silicon atom in one molecule becomes two or more); it may be one alone or a suitable combination of two Used above.

R ² is a monovalent hydrocarbon group or mercapto alkyl group having the same or different carbon number of 1 to 10, preferably 1 to 3; Examples of monovalent hydrocarbon groups having 1 to 10 carbon atoms other than mercaptoalkyl groups include alkyl groups such as methyl, ethyl, and propyl, aryl groups such as phenyl and tolyl, and carbons of these groups One or all of the hydrogen atoms to which the atom is bonded are replaced by halogen atoms such as fluorine, chlorine, etc. 3,3,3-trifluoropropyl, perfluorobutylethyl, perfluorooctylethyl, etc. Substituted with methoxypropylethoxypropyl and the like. The component (B) contains one or more mercaptoalkyl groups bonded to a silicon atom in one molecule, and the groups other than the mercaptoalkyl group bonded to the silicon atom are separated from the releasability and compatibility with the component (A). From the viewpoint, it is preferable that at least 50 mol% of methyl groups are present with respect to all of R ² in the molecule.

Examples of the mercaptoalkyl group include mercaptomethyl, mercaptoethyl, mercaptopropyl, mercaptohexyl, and the like, but from the viewpoint of availability of raw materials and ease of synthesis, mercaptopropyl is preferred. The amount of mercaptoalkyl groups in all R ² in the molecule (the amount of mercaptoalkyl groups bonded to silicon atoms relative to all organic groups bonded to silicon atoms) is preferred from the viewpoint of crosslinking efficiency It is 10 ~ 50 mol%.

R ² , e, f, g, and h are selected so that the number of mercaptoalkyl groups bonded to the silicon atom in one molecule becomes two or more. Each of e, f, g, and h is preferably f ≧ 3, g ≧ 0, and h = 0 when e = 0, and e ≧ 1, f ≧ 0, g ≧ 1, and h ≧ 0 when e ≠ 0. , More preferably, when e = 0, f ≧ 4, g ≧ 0, h = 0, and when e ≠ 0, e ≧ 2, f ≧ 0, g ≧ 2, and h = 0. In addition, 2 ≦ e + f + g + h ≦ 300, and preferably 2 ≦ e + f + g + h ≦ 200.

The blending amount of the component (B) is 1 to 30 parts by mass, preferably 2 to 25 parts by mass, and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the component (A). When the (B) component is less than 1 part by mass, the hardenability is reduced, and when it is more than 30 parts by mass, no improvement in the hardenability is observed, and further, the peelability is reduced.

[(C) component] The (C) component is a compound having a plurality of acrylic groups in one molecule, and is an adhesion-improving component of the peelable radiation-curable polysiloxane composition of the present invention. (C) A component system may be used individually by 1 type, and may be used combining two or more types suitably. Examples of the component (C) include a hydrocarbon compound having an acrylic group, a silane compound having an acrylic group, or a hydrolyzed condensate thereof. The number of acrylic groups contained in a compound-based molecule having a plurality of acrylic groups in one molecule is two or more, and preferably three or more. In particular, when a compound having three or more acrylic groups in one molecule is added, adhesion can be significantly improved.

Examples of the hydrocarbon-based compound having a plurality of acrylic groups in one molecule include bifunctional, trifunctional, and tetrafunctional acrylic compounds.

Examples of the bifunctional acrylic compound include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 1,10-decane Alcohol diacrylate, tricyclodecane dimethanol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and the like. Examples of the product include Viscoat # 700HV (bisphenol AEO3.8 mol adduct diacrylate) manufactured by Osaka Organic Chemical Co., Ltd. and the like.

Examples of the trifunctional acrylic compound include trimethylolpropane triacrylate and pentaerythritol triacrylate. Examples of the product include A-9300 (ethoxylated isotricyanate triacrylate) manufactured by Shin Nakamura Chemical, TMPEOTA (trimethylolpropane ethoxy triacrylate) manufactured by Daicel-Allenx, and Daicel -OTA 480 (glyceryl propoxy triacrylate) manufactured by Allenx Corporation.

Examples of the acrylic compound having four or more functions include pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, and A-9550 (dipentaerythritol polyacrylate) manufactured by Shin Nakamura Chemical.

Examples of the silane compound having two or more acrylic groups in one molecule include those represented by the following general formula (3). (Where n is an integer of 1 to 3, m is an integer of 1 to 10, X is an alkoxy group having 1 to 4 carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, and R ⁴ is represented by the following formula (4) or (4 '). (In the formula, A is a linear, branched, or cyclic divalent hydrocarbon group having 1 to 10 carbon atoms. It is an organic group that allows an oxygen atom or a nitrogen atom to exist therebetween, but does not include other heteroatoms. A linking group, R ⁵ is a hydrogen atom, and p is an integer of 1 to 5). (In the formula, B is a linear, branched, or cyclic trivalent hydrocarbon group having 1 to 10 carbon atoms. It is an organic group that allows an oxygen atom or a nitrogen atom to exist therebetween, but does not include other heteroatoms. As a linking group, R ⁵ is a hydrogen atom, p ′ and p ”are each an integer of 1 or more, and p ′ + p” is an integer of 2 to 5).

The formula (3) is preferably a silane compound having two or more acrylic groups in one molecule, represented by the following general formulae (5) to (8). In the formula, X and n are as described above.

Silane compounds having two or more acrylic groups in one molecule represented by the general formulae (3), (5) to (8) can be made the same as described in Japanese Patent Application Laid-Open No. 2016-041774. It is obtained by reacting a compound having an acrylic group and a hydroxyl group in the molecule with an organic silicon compound having an isocyanate group.

Examples of the organic silicon compound having an isocyanate group include 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, and 3-isocyanate. The propylmethyldiethoxysilane is preferably 3-isocyanatepropyltrimethoxysilane or 3-isocyanatepropyltriethoxysilane from the viewpoint of availability of raw materials.

Examples of the compound having an acrylic group and a hydroxyl group in the same molecule include bifunctional acryl alcohol such as 2-hydroxy-3-propenyloxypropyl methacrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate. And so on.

In the production of a silane compound having a plurality of acrylic groups in one molecule, a catalyst may be used as necessary. The catalyst may be a reaction catalyst of an isocyanate generally used, and a tin compound is preferred. Relative to 1 mol of an organic silicon compound having an isocyanate group, the amount of catalyst used is 0.0000001 to 1 mol, and more preferably 0.000001 to 0.01 mol. When used in excess of 1 mol, the effect is saturated and uneconomical. If it is less than 0.0000001 mol, the catalyst effect is insufficient, the reaction speed is low, and the productivity may be reduced.

In the production of a silane compound having a plurality of acrylic groups in one molecule, the reaction is an exothermic reaction. If the temperature is excessively high, a side reaction may occur. Therefore, the preferred reaction temperature during manufacture is 20 to 150 ° C, more preferably 30 to 130 ° C, and even more preferably 40 to 110 ° C. When it is lower than 20 ° C, the reaction speed is low, and productivity is reduced. On the other hand, when it exceeds 150 ° C., side reactions such as polymerization reaction of an organosilicon compound having an isocyanate group and polymerization of an acrylic group may occur.

A hydrolyzed condensate of a silane compound having a plurality of acrylic groups in one molecule may be used as an adhesion-improving component. As a method of this hydrolysis condensation, a conventional method can be adopted.

Examples of the catalyst for hydrolysis and condensation include acids such as hydrochloric acid, nitric acid, acetic acid, and maleic acid; alkali metal hydroxides such as NaOH and KOH; and ammonia, triethylamine, dibutylamine, hexylamine, and octylamine. Amine compounds, and salts of amine compounds, quaternary ammonium salts such as benzyltriethylammonium chloride, tetramethylammonium hydroxide, and tetrabutylammonium hydroxide, such as potassium fluoride and sodium fluoride fluoride Salts, solid acid catalysts or solid basic catalysts (ion exchange resin catalysts, etc.), organic carboxylic acids such as iron-2-ethylhexanoate, titanium naphthalate, zinc stearate, dibutyltin diacetate, etc. Acid metal salts, organic titanium esters of tetrabutoxy titanium, dibutoxy- (bis-2,4-pentanedione) titanium, tetrabutoxy zirconium, dibutoxy- (bis-2 , 4-pentanedionate) organic zirconium esters such as zirconium, alkoxyaluminum compounds such as triisopropyl alumina, organometallic compounds such as aluminum chelate compounds such as acetoacetone aluminum complex, and 3-amine Aminoalkyl-substituted alkoxysilanes such as propylpropyltrimethoxysilane, N- (β-aminoethyl) -3-aminopropyltrimethoxysilane, and the like can be used alone or in combination.

In the presence of the above-mentioned hydrolysis-condensation catalyst, water, and an optional organic solvent, a silane compound having a plurality of acrylic groups in one molecule is hydrolyzed and condensed to obtain a target substance.

The blending amount of the component (C) is 0.1 to 5 parts by mass, preferably 0.2 to 4 parts by mass, and more preferably 0.3 to 3 parts by mass with respect to 100 parts by mass of the component (A). If the (C) component is less than 0.1 parts by mass, there is no effect of improving adhesion, and if it is more than 5 parts by mass, there is no improvement in adhesion, and further, the peelability is reduced.

[Component (D)] The (D) component is a radical polymerization initiator that generates radicals by irradiation with radiation.

The radical polymerization initiator is not particularly limited as long as it has the ability to generate radicals due to radiation irradiation. Specific examples thereof include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, and 4'-isopropyl-2-hydroxy-2-methylbenzene. Acetone, 2-hydroxymethyl-2-methylphenylacetone, 2,2-dimethoxy-1,2-diphenylethane-1-one, p-dimethylaminoacetophenone, p- Tributyldichloroacetophenone, p-thirdbutyltrichloroacetophenone, p-azidobenzylidene acetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinoacetone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, benzoin , Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, diphenylethylene dione, bifenthrin, Phenyl ketone, methyl o-benzoyl benzoate, Michelin, 4,4'-bisdiethylaminodiphenyl ketone, 4,4'-dichlorodiphenyl ketone, 4-benzene Methylmethyl-4'-methyldiphenylsulfide, thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone , 2,4-diethylthioxanthone, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (py-1--1-yl) titanium, 1- (4- (2- Hydroxyethoxy) phenyl) -2-hydroxydi-2-methyl-1-propane-1-one, etc. These radical polymerization initiators can be blended with one or more according to the desired performance. Use 2 or more types.

The blending amount of the component (D) is 0.1 to 15 parts by mass, preferably 0.5 to 13 parts by mass, and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the component (A). When (C) component is less than 0.1 mass part, hardenability will fall, and when it is more than 15 mass parts, hardenability will not improve and peelability will fall.

The peelable radiation-curable polysiloxane composition of the present invention is obtained by blending the specified amounts of the above-mentioned components and mixing them, but in addition to the above-mentioned components, as the optional components, polysiloxane resin, polydioxane Additives such as methylsiloxane, fillers, antistatic agents, flame retardants, defoamers, flow modifiers, light stabilizers, solvents, non-reactive resins, and radical polymerizable compounds. The addition amount of an arbitrary component may be a normal amount in the range which does not inhibit the effect of this invention.

The "peelability" in the peelable radiation-curable polysiloxane composition of the present invention means that the cured product of the polysiloxane composition has "peelability". "Peelability" is under the conditions of [Peeling Force Test 1 of Peelable Radiocurable Polysiloxane Composition] of Example 1 below, preferably 0.005 to 10.0 N / 25 mm, and more preferably 0.01 to 8.0 N / 25mm.

[Peeling Sheet] The prepared peelable radiation-curable polysiloxane composition is applied to various substrates and is cured by radiation. For example, a peelable sheet can be obtained. It is applied to various substrates to harden its radiation. The substrate is not particularly limited, and various substrates that are generally used can be used, and examples thereof include cellophane, dowlin paper, fine paper, polyethylene laminate paper, polyester film, polystyrene film, and polyethylene. Plastic films such as films, polypropylene films, transparent resins such as polycarbonate, metal foils such as aluminum foil. In addition, the coating amount of the polysiloxane composition is not particularly limited, but usually it is only about 0.05 to 3.0 g / m ² .

When hardened by radiation, it is preferable to use a high- or ultra-high-pressure mercury lamp, metal halide lamp, xenon lamp, carbon arc lamp, fluorescent lamp, semiconductor solid laser, argon laser, He -Cd laser, KrF excimer laser, ArF excimer laser, F ₂ laser and other energy rays in the ultraviolet to visible light region (about 100 to about 800 nm). A radiation light source having a strong light intensity in 200 to 400 nm is preferred. Furthermore, high-energy radiation such as electron beams and X-rays may be used. The irradiation time of the radiation energy is usually about 0.1 to 10 seconds at room temperature. However, when the energy ray permeability is low or the film thickness of the curable composition is thick, it is preferable to take more time. If necessary, after irradiation with energy rays, it can also be heated at room temperature to 150 ° C for several seconds to several hours for post-hardening.

The peelable radiation-curable polysiloxane composition can be hardened by radiation irradiation even in the air, but in order to improve the hardenability, the oxygen concentration can be lowered and hardened. The lower the oxygen concentration, the higher the sclerosis, so the lower the oxygen concentration, the better. The oxygen concentration is 1% by volume, preferably 0.1% by volume, and more preferably 0.01% by volume. The composition of the present invention may be used by diluting it in an organic solvent as the case may be. [Example]

The synthesis examples, examples, and comparative examples are shown below to specifically explain the present invention, but the present invention is not limited thereto. In the following examples, the physical properties in the tables are measured by the following test methods. Viscosity is a value at 25 ° C. measured by a BN-type rotary viscometer.

The evaluation of the peelable radiation-curable polysiloxane composition of the present invention was performed by the following test method. [Peeling force test 1 of peelable radiation-curable polysiloxane composition] After preparing the peelable radiation-curable polysiloxane composition, it was roll-coated to a thickness of about 1.7 g / m ² . On a 38 μm polyethylene laminate paper, a high-pressure mercury lamp of 80 W / cm with two lamps was used to irradiate 100 mJ / cm ² of ultraviolet rays to form a hardened film. After the obtained cured film was stored at 25 ° C. for 20 hours, an acrylic adhesive tape TESA7475 (trade name) having a width of 25 mm was attached to the surface of the cured film, and a 2 kg roller was pressed back and forth once to produce a pressure-measuring film. sample. This sample was aged at 70 ° C for 20 to 24 hours while applying a load of 70 g / cm ² . Then, using a tensile tester, the attached tape was pulled at an angle of 180 ° at a peeling speed of 0.3 m / min, and the force (N / 25 mm) required for peeling was measured. The results are shown in Table 1.

[Residual Adhesion Test of Peelable Radiation Curable Polysiloxane Composition 1] After preparing the peelable radiation curable polysiloxane composition, roll coating was performed so as to obtain a coating amount of about 1.7 g / m ² . A hardened film was formed on a polyethylene laminated paper having a thickness of 38 μm using a high-pressure mercury lamp of 80 W / cm with two lamps and irradiating ultraviolet rays with an irradiation amount of 100 mJ / cm ² . After the obtained cured film was stored at 25 ° C. for 20 hours, an acrylic adhesive tape TESA7475 (trade name) having a width of 25 mm was attached to the surface of the cured film, and a 2 kg roller was pressed back and forth once to produce a pressure-sensitive adhesive sample. This sample was aged at 70 ° C for 20 to 24 hours while applying a load of 70 g / cm ² . Then, using a tensile tester, the attached tape was peeled at an angle of 180 ° and a peeling speed of 0.3 m / min, and the tape was attached to a SUS board. The force (Y) required for peeling was measured by pressing a 2 kg roll back and forth once and leaving it at 25 ° C for 30 minutes. Similarly, the force (Z) required for peeling TESA7475 not bonded to the hardened film from the SUS board was measured, and the value obtained by dividing (Y) by (Z) was taken as the residual adhesion rate. The results are shown in Table 1.

[Adhesion Test 1] After preparing a peelable radiation-curable polysiloxane composition, it was roll-coated on a polyethylene laminated paper having a thickness of 38 μm so as to have a coating amount of about 1.7 g / m ² , and used A two-lamp 80 W / cm high-pressure mercury lamp irradiates 100 mJ / cm ² of ultraviolet rays to form a hardened film. After the cured film was rubbed with a finger 10 times, the presence or absence of turbidity and peeling was visually observed, and evaluated by the following criteria. The results are shown in Table 1. A: No turbidity or peeling was seen. B: Cloudiness and peeling were slightly observed. C: Cloudiness or peeling was seen. D: Not hardened.

[Peeling force test 2 of peelable radiation-curable polysiloxane composition] After preparing the peelable radiation-curable polysiloxane composition, it was roll-coated to a thickness of about 1.7 g / m ² . A hardened film was formed on a polyethylene laminate paper of 38 μm in a nitrogen environment with an oxygen concentration of 150 ppm using two high-pressure mercury lamps of 80 W / cm to irradiate 100 mJ / cm ² of ultraviolet light. After the obtained cured film was stored at 25 ° C. for 20 hours, an acrylic adhesive tape TESA7475 (trade name) having a width of 25 mm was attached to the surface of the cured film, and a 2 kg roller was pressed back and forth once to produce a pressure-measuring film. sample. This sample was aged at 70 ° C. for 20 to 24 hours while applying a load of 20 g / cm ² . Then, using a tensile tester, the attached tape was pulled at an angle of 180 ° at a peeling speed of 0.3 m / min, and the force (N / 25 mm) required for peeling was measured. The results are shown in Table 2.

[Residual Adhesion Test of Peelable Radiation Curable Polysiloxane Composition 2] After preparing the peelable radiation curable polysiloxane composition, a roll coating was performed so as to obtain a coating amount of about 1.7 g / m ² . A hardened film was formed on a polyethylene laminated paper having a thickness of 38 μm in a nitrogen environment with an oxygen concentration of 150 ppm by using a high-pressure mercury lamp of 80 W / cm with two lamps and irradiating an ultraviolet ray with an irradiation amount of 100 mJ / cm ² . After the obtained cured film was stored at 25 ° C. for 20 hours, an acrylic adhesive tape TESA7475 (trade name) having a width of 25 mm was attached to the surface of the cured film, and a 2 kg roller was pressed back and forth once to produce a pressure-sensitive adhesive sample. This sample was aged at 70 ° C. for 20 to 24 hours while applying a load of 20 g / cm ² . Then, using a tensile tester, the attached tape was peeled at an angle of 180 ° and a peeling speed of 0.3 m / min, and the tape was attached to a SUS board. The force (Y) required for peeling was measured by pressing a 2 kg roll back and forth once and leaving it at 25 ° C for 30 minutes. Similarly, the force (Z) required for peeling TESA7475 not bonded to the hardened film from the SUS board was measured, and the value obtained by dividing (Y) by (Z) was taken as the residual adhesion rate. The results are shown in Table 2.

[Adhesiveness Test 2] After preparing a peelable radiation-curable polysiloxane composition, it was roll-coated on a polyethylene laminated paper having a thickness of 38 μm so as to have a coating amount of about 1.7 g / m ² . In a nitrogen environment with an oxygen concentration of 150 ppm, a two-lamp 80 W / cm high-pressure mercury lamp was used to irradiate 100 mJ / cm ² of ultraviolet radiation to form a hardened film. After the cured film was rubbed with a finger 10 times, the presence or absence of turbidity and peeling was visually observed, and evaluated by the following criteria. The results are shown in Table 2. A: No turbidity or peeling was seen. B: Cloudiness and peeling were slightly observed. C: Cloudiness or peeling was seen. D: Not hardened.

[Example 1] Uniform mixing: (A-1) 100 parts by mass of a vinyl-containing polydimethylsiloxane having a viscosity of 3,500 mPa · s at 25 ° C. as shown in the following average composition formula, (In the formula, Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group.) (B-1) A mercapto group-containing polydimethyl silicon having a viscosity at 25 ° C. of 40 mPa · s and represented by the following average composition formula: 10 parts by mass of oxane, (In the formula, Me represents a methyl group, and S represents a mercaptopropyl group) (C-1) 1.0 part by mass of 1,6-hexanediol diacrylate, and (D) a radical polymerization initiator 2-hydroxy-2- 3 parts by mass of methyl-1-phenyl-propane-1-one, and polysiloxane composition 1 was obtained.

[Example 2] Except for 100 parts by mass of a vinyl group-containing polydimethylsiloxane having a viscosity of 800 mPa · s at 25 ° C. and having a viscosity of 800 mPa · s at 25 ° C. as represented by (A) component (A-2) The same procedure as in Example 1 was performed to obtain a polysiloxane composition 2. (In the formula, Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group).

[Example 3] Except for 10 parts by mass of a mercapto group-containing polydimethylsiloxane having a viscosity of 50 mPa · s at 25 ° C. and represented by the following average composition formula (B-2) as the component (B-2), The same procedure as in Example 1 was performed to obtain a polysiloxane composition 3. (In the formula, Me represents a methyl group, and S represents a mercaptopropyl group.)

[Example 4] The same procedure as in Example 1 was carried out except that (C-2) trimethylolpropane triacrylate was 1.0 parts by mass, and a polysiloxane composition 4 was obtained.

[Example 5] The same procedure as in Example 4 was performed except that (A) component was (A-2) 100 parts by mass of a polydimethylsiloxane containing a vinyl group, and a polysiloxane composition 5 was obtained.

[Example 6] The same procedure as in Example 4 was performed except that (B) component was (B-2) 10 parts by mass of a polydimethylsiloxane containing a mercapto group, and a polysiloxane composition 6 was obtained.

[Example 7] The same procedure as in Example 1 was carried out except that the component (C) was 1.0 part by mass of (C-3) dipentaerythritol hexaacrylate, and a polysiloxane composition 7 was obtained.

[Example 8] The same procedure as in Example 7 was performed except that (A) component was (A-2) 100 parts by mass of a polydimethylsiloxane containing a vinyl group, and a polysiloxane composition 8 was obtained.

[Example 9] The same procedure as in Example 1 was performed except that the component (C) was (C-4) 1 part by mass of a silane compound represented by the following general formula, and a polysiloxane composition 9 was obtained. (In the formula, Me represents a methyl group).

[Example 10] The same procedure as in Example 9 was performed except that (A-2) 100 parts by mass of the polydimethylsiloxane containing a vinyl group was obtained, to obtain a polysiloxane composition 10.

[Example 11] The same procedure as in Example 1 was performed except that the component (C) was 1 part by mass of a silane compound represented by the following general formula (C-5), and a polysiloxane composition 11 was obtained. (In the formula, Me represents a methyl group).

[Example 12] The same procedure as in Example 11 was performed except that (A) component was (A-2) 100 parts by mass of a polydimethylsiloxane containing a vinyl group, and a polysiloxane composition 12 was obtained.

[Example 13] The same procedure as in Example 8 was performed except that the component (C) was 3.0 parts by mass of (C-3) dipentaerythritol hexaacrylate, and a polysiloxane composition 13 was obtained.

[Comparative Example 1] Except that (C-1) in Example 1 was not included, the same procedure as in Example 1 was performed to obtain a polysiloxane composition 14.

[Comparative Example 2] Except that (C-1) in Example 2 was not included, the same procedure as in Example 2 was performed to obtain a polysiloxane composition 15.

[Comparative Example 3] Except that (C-1) in Example 3 was not included, the same procedure as in Example 3 was performed to obtain a polysiloxane composition 16.

[Comparative Example 4] The same procedure as in Example 1 was carried out except that 4-hydroxybutyl acrylate (X) was replaced with 1 part by mass in place of (C-1) in Example 1 to obtain a polysiloxane composition. 17.

[Comparative Example 5] Instead of (C-1) in Example 2, except that 4-hydroxybutyl acrylate (X) was 1 part by mass, the same procedure as in Example 2 was performed to obtain a polysiloxane composition. 18.

[Comparative Example 6] A polysiloxane composition 19 was obtained by performing the same procedure as in Comparative Example 4 except that the 4-hydroxybutyl acrylate (X) in Comparative Example 4 was set to 3 parts by mass.

[Comparative Example 7] A polysiloxane composition 20 was obtained by performing the same procedure as Comparative Example 5 except that the 4-hydroxybutyl acrylate (X) in Comparative Example 5 was 3 parts by mass. Comparative Example 7 evaluated peel force test 1, residual adhesion rate 1, and adhesion test 1.

Claims (5)

A peelable radiation-curable polysiloxane composition containing the following components (A), (B), (C), and (D); (A) having an alkenyl group represented by the following average composition formula (1) Organic Polysiloxane: 100 parts by mass (In the formula, R ¹ is a monovalent hydrocarbon group having the same or different carbon number 1 to 10; a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, and 2 ≦ a + b + c + d ≦ 8,000; However, R ¹ , a, b, c, and d are selected such that the alkenyl group bonded to the silicon atom in one molecule becomes two or more); (B) has the following average composition formula (2): Mercapto alkyl organic polysiloxane: 1 to 30 parts by mass (In the formula, R ² is a monovalent hydrocarbon group or mercapto alkyl group having the same or different carbon number 1 to 10; e ≧ 0, f ≧ 0, g ≧ 0, h ≧ 0, and 2 ≦ e + f + g + h ≦ 300; however, R ² , e, f, g, and h are selected so that the number of mercaptoalkyl groups bonded to the silicon atom in one molecule becomes two or more); (C) a compound having one in plural molecules Acrylic-based compound: 0.1 to 5 parts by mass (D) Photopolymerization initiator: 0.1 to 15 parts by mass. The peelable radiation-curable polysiloxane composition according to claim 1, wherein the component (C) is a compound having three or more acrylic groups in one molecule. The peelable radiation-curable polysiloxane composition according to claim 2, wherein the component (C) is a hydrocarbon-based compound having three or more acrylic groups in one molecule. The peelable radiation-curable polysiloxane composition according to claim 2, wherein the component (C) is a silane compound or a hydrolyzed condensate thereof having three or more acrylic groups in one molecule. A release sheet, which is prepared by applying the peelable radiation-curable polysiloxane composition according to any one of claims 1 to 4 on a substrate and hardening it by irradiation with radiation.